Subject: Gauge theories of fluctuating antiferromagnetism for the cuprate superconductors

One of the most mysterious phases of the cuprate high-temperature superconductors is the “pseudogap” state: despite its Fermi-liquid-like electrical transport properties, the size of the Fermi surface is smaller than that predicted by the Luttinger theorem of Fermi liquid theory. In this talk, I will discuss gauge theories of doped fluctuating antiferromagnets that we propose as effective field theories for the pseudogap phase. By virtue of exhibiting “topological order”, these theories allow to circumvent Luttinger’s theorem while exhibiting the charge transport of a Fermi liquid. The presentation will focus on a direct comparison of predictions of these gauge theories with both numerical studies of the strongly coupled Hubbard model and high-resolution photoemission data. The good agreement can be seen as at least indirect evidence for topological order in the phase diagram of the cuprate superconductors. We will also discuss the additional symmetry breaking, such as the formation of charge-density-wave, nematic, or loop-current order, that can occur at low temperature and comment on the quantum critical point in our theory.